edu.uci.ics.jung.algorithms.layout3d
Class SpringLayout<V,E>

java.lang.Object
  edu.uci.ics.jung.algorithms.layout3d.AbstractLayout<V,E>
      edu.uci.ics.jung.algorithms.layout3d.SpringLayout<V,E>

All Implemented Interfaces:

Layout<V,E>, IterativeContext, org.apache.commons.collections15.Transformer<V,javax.vecmath.Point3f>

public class SpringLayout<V,E>
extends AbstractLayout<V,E>
implements IterativeContext

The SpringLayout package represents a visualization of a set of nodes. The SpringLayout, which is initialized with a Graph, assigns X/Y locations to each node. When called relax(), the SpringLayout moves the visualization forward one step.

Author:

Danyel Fisher, Joshua O'Madadhain

Nested Class Summary

static interface	SpringLayout.LengthFunction<E> If the edge is weighted, then override this method to show what the visualized length is.
class	SpringLayout.SpringDimensionChecker
protected static class	SpringLayout.SpringEdgeData<E>
protected static class	SpringLayout.SpringVertexData
static class	SpringLayout.UnitLengthFunction<E> Returns all edges as the same length: the input value

Field Summary

protected double	force_multiplier
protected SpringLayout.LengthFunction<E>	lengthFunction
protected int	repulsion_range
protected double	stretch
static SpringLayout.LengthFunction	UNITLENGTHFUNCTION

Fields inherited from class edu.uci.ics.jung.algorithms.layout3d.AbstractLayout

locations

Constructor Summary

SpringLayout(Graph<V,E> g)
Constructor for a SpringLayout for a raw graph with associated dimension--the input knows how big the graph is.

SpringLayout(Graph<V,E> g, SpringLayout.LengthFunction<E> f)
Constructor for a SpringLayout for a raw graph with associated component.

Method Summary

protected void	calcEdgeLength(SpringLayout.SpringEdgeData<E> sed, SpringLayout.LengthFunction<E> f)
protected void	calculateRepulsion()
boolean	done() For now, we pretend it never finishes.
protected V	getAVertex(E e)
double	getForceMultiplier()
double	getLength(E e)
int	getRepulsionRange()
SpringLayout.SpringEdgeData<E>	getSpringData(E e)
SpringLayout.SpringVertexData	getSpringData(V v)
double	getStretch()
void	initialize() Initializer, calls intialize_local and initializeLocations to start construction process.
boolean	isIncremental() This one is an incremental visualization
protected void	moveNodes()
protected void	relaxEdges()
void	reset()
void	setForceMultiplier(double force) Sets the force multiplier for this instance.
void	setRepulsionRange(int range) Sets the node repulsion range (in drawing area units) for this instance.
void	setSize(javax.media.j3d.BoundingSphere bs) When a visualization is resized, it presumably wants to fix the locations of the vertices and possibly to reinitialize its data.
void	setStretch(double stretch) Sets the stretch parameter for this instance.
void	step() Relaxation step.

Methods inherited from class edu.uci.ics.jung.algorithms.layout3d.AbstractLayout

getGraph, getSize, getVertices, getX, getY, isLocked, lock, lock, offsetVertex, setGraph, setInitializer, setLocation, setLocation, transform

Methods inherited from class java.lang.Object

clone, equals, finalize, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Detail

stretch

protected double stretch

lengthFunction

protected SpringLayout.LengthFunction<E> lengthFunction

repulsion_range

protected int repulsion_range

force_multiplier

protected double force_multiplier

UNITLENGTHFUNCTION

public static final SpringLayout.LengthFunction UNITLENGTHFUNCTION

Constructor Detail

SpringLayout

public SpringLayout(Graph<V,E> g)

Constructor for a SpringLayout for a raw graph with associated dimension--the input knows how big the graph is. Defaults to the unit length function.

SpringLayout

public SpringLayout(Graph<V,E> g,
                    SpringLayout.LengthFunction<E> f)

Constructor for a SpringLayout for a raw graph with associated component.

Parameters:

g - the input Graph

f - the length function

Method Detail

getStretch

public double getStretch()

Returns:

the current value for the stretch parameter

See Also:

setStretch(double)

setSize

public void setSize(javax.media.j3d.BoundingSphere bs)

Description copied from class: AbstractLayout

When a visualization is resized, it presumably wants to fix the locations of the vertices and possibly to reinitialize its data. The current method calls initializeLocations followed by initialize_local. TODO: A better implementation wouldn't destroy the current information, but would either scale the current visualization, or move the nodes toward the new center.

Specified by:

setSize in interface Layout<V,E>

Overrides:

setSize in class AbstractLayout<V,E>

setStretch

public void setStretch(double stretch)

Sets the stretch parameter for this instance. This value specifies how much the degrees of an edge's incident vertices should influence how easily the endpoints of that edge can move (that is, that edge's tendency to change its length).

The default value is 0.70. Positive values less than 1 cause high-degree vertices to move less than low-degree vertices, and values > 1 cause high-degree vertices to move more than low-degree vertices. Negative values will have unpredictable and inconsistent results.

Parameters:

stretch -

getRepulsionRange

public int getRepulsionRange()

Returns:

the current value for the node repulsion range

See Also:

setRepulsionRange(int)

setRepulsionRange

public void setRepulsionRange(int range)

Sets the node repulsion range (in drawing area units) for this instance. Outside this range, nodes do not repel each other. The default value is 100. Negative values are treated as their positive equivalents.

Parameters:

range -

getForceMultiplier

public double getForceMultiplier()

Returns:

the current value for the edge length force multiplier

See Also:

setForceMultiplier(double)

setForceMultiplier

public void setForceMultiplier(double force)

Sets the force multiplier for this instance. This value is used to specify how strongly an edge "wants" to be its default length (higher values indicate a greater attraction for the default length), which affects how much its endpoints move at each timestep. The default value is 1/3. A value of 0 turns off any attempt by the layout to cause edges to conform to the default length. Negative values cause long edges to get longer and short edges to get shorter; use at your own risk.

initialize

public void initialize()

Description copied from class: AbstractLayout

Initializer, calls intialize_local and initializeLocations to start construction process.

Specified by:

initialize in interface Layout<V,E>

Specified by:

initialize in class AbstractLayout<V,E>

calcEdgeLength

protected void calcEdgeLength(SpringLayout.SpringEdgeData<E> sed,
                              SpringLayout.LengthFunction<E> f)

step

public void step()

Relaxation step. Moves all nodes a smidge.

Specified by:

step in interface IterativeContext

getAVertex

protected V getAVertex(E e)

relaxEdges

protected void relaxEdges()

calculateRepulsion

protected void calculateRepulsion()

moveNodes

protected void moveNodes()

getSpringData

public SpringLayout.SpringVertexData getSpringData(V v)

getSpringData

public SpringLayout.SpringEdgeData<E> getSpringData(E e)

getLength

public double getLength(E e)

isIncremental

public boolean isIncremental()

This one is an incremental visualization

done

public boolean done()

For now, we pretend it never finishes.

Specified by:

done in interface IterativeContext

reset

public void reset()

Specified by:

reset in interface Layout<V,E>